Hey Rigadigadoon, I was just looking at the pictures again and there's a few easy fixes to your canteens and breadbags.
1. The canteen how it is now is kind of just hanging from the belt. It actually was attached to a D-ring near the breadbag loop and to keep the canteen secure the strap fit through the one leather loop on the exterior of the breadbag. As shown:
Also if you could add a bit of bulk to the breadbag as it typically carried quite a bit of stuff in there like rations, one's fieldcap, and other miscellaneous stuff that one would like to carry around. Also the cup in the picture could've either been rigged like that but was most likely put in the breadbag so it wouldn't rattle around.